Printing press



1945. w. w. DAVlD SON Re. 22,702

Him-fine PRESS Original Filed 001:. '5', 1939 4 Sheets-Sheet l Dec. 4, 1945. w w DAVlDSON Re. 22,702

' PRINTIIIQG PRESS Original Filed 001:. 5, 1959 4 Sheets-Sheet 2 I r I I 12% Wdfiamdsozz m I Dec. 4, 1945.

w. w. DAVIDSON 2 PRINTING PRESS 4 Shets-Sheet 3 Original Filed 0cr.. 3, 1959 mentor: ifilliclflLif a/d Dal/1160121 w. w. DAVIDSON PRINTING PRESS Dec. 4, 1945.

Original Filed Oct. 3. 1939 4 Sheets-Sheet 4 Reissued Dec. 4, 1945 PRINTING PRESS William Ward Davidson, Evanston, Ill., assignor to Davidson Manufacturing Corporation, Chicago, Ill., a corporation of Illinois Original No. 2,280,799, dated April 2s, 1942, serial No. 297,745, October 3, 1939. Application for. reissue January 29, 1944, Serial No. 520,351

21 Claims.

In some types of printing presses, it is necessary to provide a sheet delivery apparatus which grasps the sheet and draws it away from the printing rolls. With small sheets an efficient stripping blade may be satisfactory but with large sheets, especially thin sheets which have very little rigidity, a press with such a stripper cannot throw the sheets out uniformly and dependably. With large presses it is, therefore, customary to provide means for gripping the leading edge of the sheet adjacent to the printing, rolls and pulling the sheet away to a desired position at which it is released to fall onto a stack. These gripping means are sometimes carried by chains and are appropriately called chain deliveries.

It has also been common to provide gripping means on the printing cylinders, as, for example, on the blanket rolls of an offset printing press. This latter type of gripping means, together with a registration stop coacting therewith, has been considered necessary to secure accurate registration. These registration grippers usually passed the sheet to the delivery grippers, which were carried by their chains around sprockets tangential to the blanket roll. According to the present invention, the chains are carried on sprockets concentric with the blanket roll with resultant simplicity and compactness. According to one form of the invention, a single gripping mechanism is made to serve both purposes with resulting economy and simplicity.

The compactness and simplicity are especially notable and satisfactory because of the use of a particular type of press in combination with the above described feature of having the chain delivery run around one of the printing cylinders. The press referred to is an oifset press in which the blanket roll is positioned generally below the platen roll, as in a two-roll press in which the upper roll serves both as a plate roll and a platen roll. With this type of press, the sheetis printed on its underside, and it has been common, therefore, to carry it half -way around the blanket roll so as to turn it over. Thus, the heet is fed into the press at one side thereof, carried half-way around the blanket roll, and ejected from the press at the same side of the press on which it was fed to the press. This fact is ingeniously used according to the illustrated embodiments of the present invention by providing a chain gripping mechanism in which the grippers follow the simple path of a single closed loop. In short, the chains form. a single loop extending around the blanket roll, approaching it and departing from it on the same side of the press, namely the side at which the sheets are fed. and delivered. As.

thus ensure accurate registration. 'As the sheet.

passes half-way around the roll, it is gripped or continues to be gripped by the grippers carried by the chain which draw it away from theroll to a delivery position at which time the grippers. are opened and the sheet is-dropped on a-stack.

Additional advantagesandobjects of the invention will be apparent from the following description and from the drawings, in which.

Fig, 1 is a somewhat diagrammatic view of one form of the invention chosen for illustration.

Fig. 2 is a somewhat diagrammatic sectional illustration showing the grippers of the roll gripping a sheet which has just been fed to them, While the grippers of the chain remainopen.

Fig. 3 is a corresponding View showing the,

chain grippers stripping the sheet from the. blanket roll.

Figs. 4 and 5 are somewhat diagrammatic illustrations indicating the final steps in the operartion of the feeding mechanism.

Fig. 6 is a somewhat diagrammatic fragmemtary plan view of the registration and delivery mechanism of Figs. 1 to 3.

Fig. 7 is a. somewhat diagrammatic fragmentary detail sectional view taken approximately on the line 'l-l'of Fig. 6,

Figs. 8 and 9 are views corresponding to Figs. 6 and 7 but showing a modified and simpler form of the invention.

Two preferred embodiments of the invention havebeen shown in the drawings and will hereinafter be described all as required by section 4888 of the Revised Statutes, but many other forms could. be used within the spirit of the invention.

In the formof the invention chosen for illustration, the printing press includes a frame I 0, printing rolls H and I2, inking rolls I3, dampening rolls I l, final feeding mechanism indicated generally at l6, and preliminary feeding or separating mechanism indicated generally at ll, all The of which may be of conventional typesseparator ll. separates sheets from a stack l8.

Of course, the term. printing press might. be

used more narrowly to include. onl the printing rolls II and I2.

The printing roll I l is a. dual purpose roll, having a plate 2| on one side thereof and a platen surface 22 on the other side thereof. The roll I 2 is a blanket roll ortransfer cylinder, being provided with a blanket 23. It is thus seen that in its illustrated form, the press is of the type known as a two-roll offset press. In the general operation of this 'press the plate 2|, which bears the matter to be printed, is rotated in contact with the dampening rolls l4 and is then inked by the inking rolls I3. It then rotates in direct contact with the blanket 23, transferring the ink thereto. During this application of ink to the blanket 23, the blanket roll I2 makes a revolution without any sheet in contact therewith and hence without performing a printing function. On its next revolution, a sheet is fed to the blanket roll I2 and pressed thereon by the platen surface 22 The sheet separating and feeding means may be of any suitable form; It is illustrated as including an advancing roller 26 which is driven intermittently to draw a sheet from the pile I8 at the proper time during each revolution of the roll II. a retard roller 21 for preventing more than one sheet from being fed at a time, and pull-out rollers 28 for drawing the sheets out after the driving of roller 26 has ceased, the roller 26 being provided with an over-running clutch. Inclined conveyor belts 29 urge the sheet against the side guide 3| to provide lateral registry against stop fingers 32 to provide preliminary end registry. While the sheet is thus pressed against stop fingers 32, pressure roller 33 is lowered by the cam 34 of Fig. to cooperate with feed rollers 1.

36 in gripping the sheet; When the sheet is thus firmly gripped, cam 31 of Fig. 4 drives a gear segment 36 to rotate stop fingers 32 and feed roller 36 to feed the sheet, the shape of the cam 31 and the positions of the parts being such that the sheet is rapidly moved at a speed in excess of the peripheral speed of rolls II and I2,

To provide final accurate registration, stop fingers 4| are, in the form seen in Fig. 2, provided on roll I2 and the sheet 42 is fed against these stop fingers by feeding roller 36 actuated as stated, by cam 31. The sheet 42 is preferably overfed slightly by roller 36 so as to be buckled and pressed firml against the stop fingers 4|. While it is thus pressed firmly against the stop fingers 4 I, gripping fingers 43 are closed upon the sheet 42, clamping it against an anvil 44. These grippers comprising the fingers 43 and anvil 44 holdthe sheet firmly in its registered position and carry it beyond the line of the bite between rolls II and [2 where it is firml seized by these rollers. Once it is seized in this bite, the ac curacy of registration is determined since the rolls I I and I2 themselves prevent shifting of the sheet out of registration.

A second set of grippers comprising anvils 46 and grip fingers 41 is carried by chains 48. One of the chains 48 is positioned adjacent each end of the roll I2, one end of the roll being shown in Figs. 6 and 7 and the other end being a substantial duplicate thereof insofar as the chains 49 are concerned. As seen in Fig. 7, each set is carried on a sprocket 49 rotating with the roll l2. The other end of each chain is carried by a sprocket 5| mounted on a shaft 53 carried by the frame I ll of the press. Carried by the chains 48 and extending between them are three angle bars 52 spaced apart on the chains a distance corresponding to the periphery of the sprocket 49. Each angle bar 52 carries anvil fingers 46 and supports the grip fingers 41 which are carried by and keyed to shaft 53. The shafts 53 are journaled in brackets 54 carried by angle bars 52. Each shaft 53 has an operating lever 56 secured at its end, the lever 56 bearing a roller 51 which is adapted to engage cam 58.

As each bar 52 approaches the roll l2 or the feeding position thereon, roller 51 rides up on cam 58 thereby turning shaft 53 and opening grip fingers 41 to the position shown in Fig. 2.

-The grip fingers 43 are in the meantime held open by cam 59 engaging roller 6| on arm 62 which actuates shaft 63 carrying the grip fingers 43. When the sheet 42 has been fed against the stops 4|, roller 6| rides oif,of the high portion of cam 59 and permits fingers 43 to close on the sheet 42.

After the rolls rotate further and the sheet 42 has been gripped in the bite between rollsI I and I2, roller 51 rides off of cam '56, permitting the second set of grip fingers 41 to close upon the sheet 42, as seen in dotted lines in Fig. 3, under the influence of spring 64. After fingers 41 have closed upon the sheet 42, roller 6| rides onto the highest portion 65 of camr59 thereby opening the first grip fingers 43 to the position shown in Fig. The bar 52 is now carried b the chains 48 away from the roll I2, the grippers 46 and 41 carried by the bar 52 pulling the sheet 42 off of the roll I2 as seen in full lines in Fig. 3. It will be observed that because of the fact that the two sets of grippers are in alignment through a substantial part of the revolution of roll l2, the closing of one set of grippers and the opening of the other may be performed quite leisurel and there is no necessity for delicate adjustment of these opening and closing times as would be the case if a sheet were being passed from grippers on one roll to grippers on another roll or a chain I tangentially disposed with respect to the first roll.

The sheet 42 continues to be gripped by the grip rs 46 and 41 until the sheet has been drawn to a position over the pile 66 or over any other suitable discharge receptacle or table, at which time the roller 51 strikes cam 61, and the grip fingers 41 are opened to release the sheet 42 so that it may drop upon the pile 6-6.

As the roll I2 continues to rotate, roller 6| rides off of the extremely high portion 65 of the cam 59 and onto the intermediate portion 68 thereof, thereby permitting the fingers 43 to assume an intermediate position approximately even with the outer ends of stop fingers 4| so that they in effect form an overhanging extension for the stop fingers 4| to positively prevent the next sheet 42 from buckling over and slipping past the stop finger 4|. It will also be observed that as the sheet 42 is fed to the stop fingers 4| the gripper fingers 41 are positioned approximately even with the top of the stop fingers 4| and have upwardly curved toes so that they also aid in guiding the sheet 42 to its proper position against the stop finger 4|. As a matter of fact, at the time that the sheet is fed to the stop finger 4| it is inclined somewhat toward the feed roller 36 so that when the sheet strikes the stop 4| it tends to slide down the stop 4| (if not alzerosgrip-"fiii g'e'r' '41 {is not "closed on me sweet- 42""- until after; the sheet 42 has been engaged by therollsl l arr-r112 for the reason that-this may ive greater certainty of registration in" that therewill "be'absolutely nochance that movement ofthegripfingers 46 and 41 with respecttotheroll' l2 willshift the'sheet'fli In short, during the-"crucial" period this form of the invention oon'te'r'nplatesthat the sheet 42 will be inton tro'lof the gripping fingers 43 and the anvil 44 which are immovable with respect to the 'roll I2 except the opening motion of I grippingfingers 43," which motion -'-does"not occur during the crucial "registration pearicdi It will be observed that the anvil-'44 isin'fact a bar"'exten'ding"acrosstheroll l2'and it'may be thebar 'us'ed'for' securing one end of theblanket" 23: This anvil-or bar "44 is notchedas' seenat" 1 i to receive the anvil fingers; Although experi ence' may show that "with "some presses more is believed thattwo grippers each comprising an anvil 46and 'a gripping finger 4'! will be'sufficient' if they are positionedjustclose enough together to'receive'the narrowest sheets which are likely to"'be" run" on" the press, being spaced approximate'ly' equally from "the center ofthe roll. It may" be desirableto 'providea' larger number of the "regi'sti'ation' grip fingers 43and to'make them adjustable so' that one of"themma'y"always' be positioned near each'oute'r'edge of'the sheet with intermediate "'grippers'in'theoase of wide sheets" sothat the sheet may'be held with maximum" firmness.- To this end the gripping finger 43 may" be adjust'ably pos'itionedon shaft 63 by "set screw 13, the'stop finger43'being maintained'in' con stant angular position with'respect to shaft 63 by" some sort of splining arrangement or"non"-' circular engagement'wit'h' the'shaft'GS. A separate collar l4 may' be provided for effectively connecting "a spring 16 toshaft 63 to urge the fingers 43in the closed direction,

As seen in Fig. "7, the hub I8 of the roll l2 'rotates with the roll and, indeed, may beused for drivingithe roll! It is therefore necessary that the cams 58'and 579' be supported independently of-the shaft 'I9,' whi'ch carries roll I2,'and therefore brackets 81 ma be provided for 'these'ca'ms as seen in Fig. 6, these brackets of course extending around amoving part of the press to'a stationary portion or the frame.

lt will' be observed that the end Walls of roll are-cut out as seenat 83 andthe end Walls of 'rollIl are cut out as seen at 84 for the purpose of making room for the passage of the transverse members of the chain delivery, namely the bar- 52"an'd the shaft 53} If, as illustrated in Fig. l, thechain is of a length corresponding "to' three revolutions of blanket roll II, it must be provided with a crossbar 52' for each. revolution. In this event the walls of roll] I should be cut out at 85at a position diametrically opposite the cutcuts 84. Howevenif chain 48 were one revolution longer, the Crossbars 52 could be spaced two revolutions apart and the cut-out 85 would not be needed. It will be observed that it is not nee-es sary for these transverse members or any other part: the chain delivery to'contact either the roll ll or the roll 12 since the sheet'is registered independently "or their exact positlbningwltlljrc spect to 'the'rolls II and I2.' Thi 'is Very desirable because if it is attempted to position th'echain delivery? with" exactltu'de'"with respect to the roll I 2 by" havihgit wedged into V-shaped formations thereof: forexamplefa yery hoisymachine-lslike grippers 'aredesirablefor'the chain delivery; it

qui-red to avoid the noise.

In Figs. 8 and 9 aform'of the invention .has;

1y to result-or considerable expense: may be re-" It-is accomplished, however, by the very simple ex Dedient of utilizing stop fingers which are independent of variations between successive chaincarried grippers, as are stop fingers 4| carried *by the roll l2,and taking advantage of the fact that-'regardless of 'variations in the relative positioning of cross bars 52' with respect to the roll l2 on successive occasions of their meetin 1 there "will ordinarily be no variation in their relative positions during the occasion of one meet ing after the links by which the cross bars 52' are carried have been fully eated on the sprocket wheels. It has previously been contemplated to accurately position a crossbar such as the crossbar 52, carrying gripping fingers and even stop means, by a V-type of coaction between such crossbar and the roll I2 which would automatically self-position the crossbar. Although this is a possible way of obtaining at least fairly good registration, the method illustrated in Figs. 8 and 9 isconsidera'bly simpler and at the same time mor accurate and also quieter in operation.

The'gripping fingers 41' are carried and 0perated by shaft 53" as seen in Figs. 1 to 7, although they may be longitudinally adjustable thereon if desired and more than two of them may be provided. These gripping fingers 4'! are controlled by roller 51 in coaction with stationary cam 86. The position of cam 86 and the angularity of chain 48 should be such that at the time the roller 51' rides off of the cam 86 the links 81 to which the crossbars 52' are secured have become firmly seated on sprocket 88. It is not essential that the links 81 assume exactly the same position on the sprocket 88 each time that they enga e it, but it is merely essential that on'ce'they are seated thereon they should not move with respect to it until after the sheet has been seized'in the bite between the rolls II and I2. To this end the chain 48 could extend at a steeper angle than shown in Fig. 9 or the cam 86' could be extended to the left if it should be found that the fingers 41' were closing before the crossbar 52 had found its final position. Some suitable 'means, not shown, should be provided for'shifting the shaft 53 in a direction to tighten the chains 48.

Fingers 41 will be urged to the closed position bysprings 89. His possible that if these springs are exceptionally strong the cam 86 may result in rocking the bar 52' slightly and thereby causing an undesirable movement of the sheet 42 with respect to the stop fingers 4|. If such should develop, this can be remedied by replacing "the springs 89 with weaker springs. If with a particular press and a particular type of work it is found that the sheet is not then gripped firmly enough, other means for operating'the grip fingets 41 maybe provided; For example, they'- could be operated by'beveled'pins operating arms" at each "end of "the shaft 53, each of the beveled pins'being" moved in'a direction parallel to the shaft'by cams engaging the'ends thereof so' that ,fi eforces eXerted-bythe cams will be in a di- -rection*axialof the shaft 53- andwilicancel-one another. Likewise, the fingers 41' could be operated by rocker members fulcrumed or pivoted on g the crossbar 52' and operated by a cam which to receive the transverse portions of the gripping mechanism, namely the crossbar 52' and the shaft 53'.

Of course, the notches 85 would likewise be pro- I Vided as explained in connection with Fig. 1.

The anvil 9| has been illustrated as one flange of the angular crossbar 52', this flange being slotted at 92 to receive the stop fingers 4|. It should be observed that the size of the notches 83' and 84' and the slot 92 are such that there is no contact between the portions of the gripping mechanism carried by the chain and any other rotating mechanism except the sprocket wheels carrying the chains. This permits the press to be quite quiet in operation.

Except for the differences mentioned and apparent fromv the drawings, the construction and operation of the form of the invention shown in Figs. 8 and 9 may be the same as that of the form shown in Figs. l'to '7.

From the foregoing it is seen that a press is provided having in conjunction therewith a chain delivery which is in its simplest possible form in that it comprises a single loop and extends around the shaft of one of the printing rolls so that a minimum of shafts and working parts maybe used. Furthermore, the chain delivery drops the sheet printed-side-up so that the condition of the printing may be observed. In addition, the sheets are discharged at a position underneath the feeding conveyor table so that the overall length of the entire machine may be a minimum. In spite of this simplicity there is no interference with the accurate registration of the sheet since registration mean may be provided in the same manner as if the chain delivery were not provided or extended around a different shaft than either of those on which the printing rolls are mounted. Furthermore, according to one form of the invention additional simplification is possible by omitting the gripping fingers from the printing roll and letting the gripping fingers of the chain delivery perform their function, accurate registration being obtained nevertheless by virtue of the mounting of the stop fingers independently of the chains, as on the printing roll, and designing the machine so that the gripping fingers are used only during the time that they are stationary with respect to the roll, irrespective of whether or not they may be in exacly the same position with respect to the roll the next time they areused for registration.

I claim:

1. An offset printing press including a blanket roll, a platen above the blanket roll, registration stop means carried by the blanket roll, feeding means adapted to feed sheets against the stop means, grippers associated with the blanket roll at least at the time a sheet is fed to the stop means, and means for holding said grippers open at that time and for closing at least part of them while the sheet is pressed against the stop means to hold the sheet in registration, at least part of the grippers being carried by endless means around the blanket roll and away therefrom for the other to form a bite, registration stop means stripping the sheet from the blanket roll and delivering it at the desired point of delivery.

2. An offset printing press including a blanket roll, a platen above the blanketroll, and registration and delivery means including gripping means, means causing the gripping means to approach the roll, close upon the leading end of a sheet to be printed, assume a fixed position with respect to .the roll and rotate about half a revolution with the roll, pass away from the roll generally toward the direction from which it approached the roll, and open to release the sheet at a point remote from the roll; means for feeding a sheet into the gripping means, and registration stop means which, as the gripping means closes on the sheet, is associated with the gripping means and is in an exactly predetermined position circumferentially with respect to the roll, to register the sheet with the roll.

3. An offset printing press including a blanket roll, a platen above the blanket roll, and registration and delivery means including gripping means, means causing the gripping means to approach the roll, close upon the leading end of a sheet to be printed, assume a fixed position with respect to the roll, pass away from the roll, and open to release the sheet at a point remote from the roll; means for feeding a sheet into the gripping means, and registration stop means which, as the gripping mean closes on the sheet, is associated with the gripping means and is'in an exactly predetermined position circumferentially with respect to the roll, to register the sheet with the roll.

4. An offset printing press including a blanket roll, a platen above the blanket roll, and registration and delivery means including chains each forming a simple closed loop extending around the axis of the blanket roll and off to one side thereof, gripping means carried by the chains, approaching the blanket roll and opened to receive a sheet at the upper side of the blanket roll, closed upon the sheet, and opened to release the sheet after passing around the blanket roll and tion stop means associated with the gripping means at the time that the sheet is fed thereto,

the stop means being accurately positioned with hold the sheet in registration for the printing thereof, and subsequently opening them to release the sheet, a second set of grippers carried by endless means extending around the axis of the roll, and moved by the endless means through the bite approximately in alignment with the first grippers and away from the roll, and means for opening the second grippers a the sheet is fed against the stop means, holding them open until the sheet has been seized by the bite, thereafter closing the second grippers to engage the sheet and carry it away from the roll after the first 0 grippers have opened, and for opening the second grippers to release the sheet at the desired delivery point.

6. A printing press including two printing members, one of which is a roll coacting. with carrying the sheet away therefrom, and registra-' second :grippers.

partied-by one .of the printing ,members,means for feeding a sheet toward the bite and against feeding means, held in registration for printingand carried away from theroll, and for opening the grippers to release the sheet at the-desired delivery point.

7. A printing press including two printing members, one of which is a rollcoacting with:

the other to form a bite. registrationstopmeans and grippers carried by the roll; meansrforfeeding a sheet toward the bite and against the stop means. means for'opening the-grippers to ,re-

ceive the sheet, closing them to hold the isheet; in registration for the printingthereof, and sub- ;seouently opening them to release the sheet, a -:second set of grippers-carried by'endless means extending around the axis of therollsandmoved by t e endless means through the bite 'approximately in ali nment with the first, grippers, and away from theroll,-. andrmeansfor opening the a secondgrippers as the sheetis 'fedagainst the stop means; holding them:open, until the'sheet has been seized'by-the bitegthereafter closing the second grippers to enga e the sheet andcarry it awav from the roll after the firstgrip'oers have .-opened. and for opening the second "grippers to release the sheet at thedesired delivery point.

1 8. A printing ress including a-rotatineunit. a; first set of rippers carried by the-rotatingunit, a second set of rip ers carried by endless-means extending around the a rotat ngunit and away therefrom, the two sets of grippersbeing in: alignment with one. another for: a 'substantialpart of ;the revolution of the rotatingxunitrmeansfor o ning the second gr pers to receive a sheet which during a part of the'period-ofali nment is I grip ed by the first rippers. and-:means for closina the second grippers-on the sheet and opening the first rippers durin theremainder offlthe period of alignment to pass the sheet to the control of the second grippers" whereby the sheet will be drawn away from'therotating unit by the 9. The combination of a printing press includ ing a printing roll, chains extending partly around the axis of the printing roll, rotating with the nrintin'g'roll and extend ng away therefrom. gripping means carried 'by thechains and at times ri idly disposed'with respect to the print ng roll means for feeding asheet to the r nnin means. and in predetermined re istration with the printing roll. -means=:for' openin the rinnin means to receive a s eet as it is fed to theripping means andfor' closing-the gripp n means af er the sheetis' fed"thereto,--and I while t e grippin means isheldrigidly disposed with respect to the printing rolland means for again opening the-gripping means iafter'the gripping means has carried the sheetvaway from the printing roll to releasethe-sheetatthe desired delivery point.

. A printing press includin tworprinting -cmembers, one'of: which-is a. roll coacting with nthe other to form a bite; registration stop means locatedin the same circumferential position with respect to the roll for successive sheets being *printed and rotating with the roll. during;v at least a part of the feeding and-printing operation,

,means for feeding asheet toward the bite and ,against the stopmeans, grippers carried by end- 'less means extending around the axis of the roll, andmoved by the endless means through the bite 5 and, away from the roll, and means for opening the grippers as the sheet is fed against the stop- .means, closing the grippers to engage the sheet .while the sheet is pressed against the stop means by the feeding means, held in registration for printing, and carried away from the roll, and for opening the grippers to release the sheet at the vdesired delivery point.

'11., A printing press including two printing members, one of which is a roll coacting with the other to form a bite,.grippers carried by endless means around the roll, through the bite and away from the roll, registration stop means rig- ..idly located circumferentially of the roll with respect to the grippers and in alignment with the grippers at the time that the sheet is fed thereto, means for. feeding a sheet toward the bite and into the grippers, and means for opening the grippers as the sheetvis fed thereto, closing the grip- 1 pers to engage the sheet while the sheet is pressed against the stop means by the feeding means, 1 held in registration for printing, and carried away fromthe. roll, and for opening the grippers to release the sheet at the desired delivery point.

12. A printing press including two printing members, one of which is a roll coacting with the other to form a bite, grippers carried by endless rmeans around the roll, through the bite and away from the roll, registration stop means rigidly located circumferentially of the roll with respect to the-grippers and in alignment with the grippers at the time that the sheet is fed thereto, means for feeding a sheet toward the bite and into the grippers, and means for opening the grippers as the sheet is fed thereto, closing the grippers to engage the sheet while the sheet is pressed; against the stop means by the feeding means, held in registration for printing, and carried away from the roll,.and for opening the grippers tolrelease the sheet at the desired de- 45 livery point, said rollbeing free of sheet-gripping means other than the grippers carried by the endless means.

13. An offset printing press including a blanket roll, a, platen above the blanket roll, registration stop means carried by the blanket roll, feeding means adapted to feed sheets against the stop means, grippers associated with the blanket roll at least .at the time a sheet is fed to the stop means, and means for holding said grippers open at that time and for closing at least part of them while the sheet is pressed against the stop means to hold the sheet in registration, the grippers being ,carried by endless. means around the blanket roll. and away therefrom for stripping the sheet from the blanket roll and delivering it at the desired point of delivery; said blanket roll ,,being free .of sheet-gripping-means other than the grippers carried by the endless means.

v-14. The combination of a printing press including a printing roll, chains extending partly around the axis of the printing roll, rotating with the printing roll and-extending away therefrom,

gripping means carried by the chains and at ping means is held rigidly disposed with respect to the printing roll, and means for again opening the gripping means after the gripping means has carried the sheet away from the printing roll to release the sheet at the desired delivery point said chains being endless and carrying said gripping means around a loop to turn the sheet over between the printing of the sheet and the release of the sheet whereby the printed face of the sheet is visible when delivered.

15. The combination of a printing press including a printing roll, chains extending partly around the axis of the printing roll, rotating with the printing roll and extending away therefrom, gripping means carried by the chains and at times rigidly disposed with respect to the printing roll, means for feeding a sheet to the gripping means, and in predetermined registration with the printing roll, means for opening the gripping means to receive a sheet as it is fed to the grip-' ping means and for closing the gripping means after the sheet is fed thereto and while the gripping means is held rigidly disposed with respect to the printing roll, and means for again opening the gripping means after the gripping means has carried the sheet away from the printing roll to release the sheet at the desired delivery point, said feeding and registering means including stop means positioned uniformly with respect to the printing roll each time the gripping means receives a sheet for cooperating with the gripping means and accurately registering a sheet with respect to the printing roll,

16. A printing press including two printing members, one of which is a roll coacting with the other to form a bite, a set of grippers carried by endless means around the roll, through the bite and away from th roll, registration stop means having the same position circumferentially of the roll for successive sheets fed thereto and, at the time each sheet is fed thereto, being rigidly located circumferentially of the roll with respect to the grippers and in alignment with the grippers, means for feeding a sheet toward the bite into the grippers and against the stop means, and means for opening the grippers as the sheet is fed thereto, closing the grippers to engage the sheet while the sheet is pressed against the stop means by the feeding means, held in registration for printing, and carried away from the roll, and for opening the grippers to release the sheet at the desired delivery point.

17. A printing press including printing rolls forming a bite therebetween, and chain registration-delivery means including sprockets rigidly mounted with respect to one of said rolls and rotating therewith, a pair of chains extending around said sprockets and each having a length corresponding to a number of revolutions of saidsprockets and a gripping unit carried by said chains and cooperating with said rolls to deliver sheets to the bite for separate printings by said rolls, means for feeding a sheet for each said printing and positioning it to be gripped by the gripping unit in a predetermined position for producing a predetermined registration relative to the printing rolls when the gripping unit carries the sheet to the printing positionwhereby successive printings of the same sheet by said rolls will be in substantially perfect registry independently of the position of the gripping unit relative to the printing rolls, and means for opening the gripping unit and closing it upon the sheet so positioned; said gripping unit from the time that it closes upon the sheet until after ithas carried.

the sheet to the position of printing being carried by portions of the chains which are in wrapped engagement with the sprockets whereby the positioning of the gripping unit with respect to the roll Will be uniform during said time.

18. The combination of a printing press including a printing roll, chains extending partly around the axis of the printing roll, rotating with the printing roll and extending away therefrom, gripping means carried by the chains and at times rigidly disposed with respect to the printing roll, means for feeding a sheet to a predetermined disposition in the path of the gripping means for registration in which disposition it may be seized by the gripping means while the gripping means is rigidly disposed as stated, means for opening the gripping means to receive a sheet and for closing the grippingmeans upon the sheet in said disposition while the gripping means is held rigidly disposed with respect to the printing roll, and means for again opening the gripping means after the gripping means has carried the sheet away from the printing r011 to release the sheet at the desired delivery point, said feeding and registering means including stop means positioned uniformly for different printings to obtain uniform positioning of different sheets in said predetermined position to produce uniform registration in printing with said printing roll.

19. A printing press includin a pair of printing members, one of which is a roll forming a bite with the other, chain-registration delivery means including sprockets rigidly mounted with respect to said roll and rotating therewith, a pair of endless chains extending around said sprockets and away therefrom and a gripping unit carried by said chains for delivering sheets to said bite, registration stop means, means for feeding successive sheets into the path of the gripping unit around said sprockets and against said registration stop means, all of the sheets to be printed by said printing members being fed against the same registration stop means whereby variations between different stop means are avoided, and means for opening the gripping unit and closing it upon a sheet While the longitudinal position of the sheet is determined by said registration stop means, said gripping unit from the time that it closes upon the sheet until after it has carried the sheet to the bite being carried by portions of the chains which are in wrapped engagement with the sprockets whereby the positioning of the gripping unit, with respect to the roll will be uniform during said time.

20. A printing pressincluding a pair of printing members, one of which is a roll forming a bite with the other, chain-registration delivery means including sprockets rigidly mounted with respect to said roll and rotating therewith, a pair of endless chains extending around said sprockets and away therefrom and a gripping unit carried by said chains for delivering sheets to said bite, registration stop means, means for feeding successive sheets into the path of the gripping unit around said sprockets and against said registration stop means, all of the sheets to be printed by said printing members being fed against said registration stop means uniformly positioned, and means for opening the gripping unit and closing it upon a sheet while the longitudinal position of the sheet is determined by said registration stop means, said gripping unit from the time that it closes upon the sheet until after it has carried the sheet to the bite being carried by portions of the chains which are in wrapped engagement with the sprockets whereby the positioning of the gripping unit with respect to the roll will be uniform during said time.

21. A printing press comprising printing rolls forming a bite therebetween, and chain registration-delivery means including sprockets rigidly mounted with respect to one of said rolls and rotating therewith, a, pair of chains extending around said sprockets, each having a length corresponding to a number of revolutions of said sprockets and a plurality of gripping units carried by the chains and cooperating with said rolls to deliver sheets to the bite for separate printings by said rolls, means for feeding a sheet to each gripping unit while it is supported on said sprockets, registering the sheet relative to the printing rolls independently of the exact location of the gripping unit relative to the printing rolls, and gripping the sheet when so registered, whereby successive printings of the same sheet by said printing rolls are made with substantially perfect registration regardless of which gripping unit carries the sheet through the bite and its precise location relative to the printing rolls.

WILLIAM WARD DAVIDSON. 

